This is an automated email from the ASF dual-hosted git repository. leborchuk pushed a commit to branch REL_2_STABLE in repository https://gitbox.apache.org/repos/asf/cloudberry.git
commit 9f3990bf5ee8531c3c2e8e7ff73a2b0ef233d946 Author: Tom Lane <[email protected]> AuthorDate: Mon Dec 11 11:51:56 2023 -0500 Be more wary about OpenSSL not setting errno on error. OpenSSL will sometimes return SSL_ERROR_SYSCALL without having set errno; this is apparently a reflection of recv(2)'s habit of not setting errno when reporting EOF. Ensure that we treat such cases the same as read EOF. Previously, we'd frequently report them like "could not accept SSL connection: Success" which is confusing, or worse report them with an unrelated errno left over from some previous syscall. To fix, ensure that errno is zeroed immediately before the call, and report its value only when it's not zero afterwards; otherwise report EOF. For consistency, I've applied the same coding pattern in libpq's pqsecure_raw_read(). Bare recv(2) shouldn't really return -1 without setting errno, but in case it does we might as well cope. Per report from Andres Freund. Back-patch to all supported versions. Discussion: https://postgr.es/m/[email protected] (cherry picked from commit 07ce2432682d1b2d593d15283fe66e88cb27285e) --- src/backend/libpq/be-secure-openssl.c | 15 +++++++++++---- src/backend/libpq/pqcomm.c | 22 ++++++++++++++++------ src/interfaces/libpq/fe-secure-openssl.c | 16 ++++++++++++---- src/interfaces/libpq/fe-secure.c | 7 +++++++ 4 files changed, 46 insertions(+), 14 deletions(-) diff --git a/src/backend/libpq/be-secure-openssl.c b/src/backend/libpq/be-secure-openssl.c index e39952494e6..25afb28facd 100644 --- a/src/backend/libpq/be-secure-openssl.c +++ b/src/backend/libpq/be-secure-openssl.c @@ -450,6 +450,7 @@ aloop: * per-thread error queue following another call to an OpenSSL I/O * routine. */ + errno = 0; ERR_clear_error(); r = SSL_accept(port->ssl); if (r <= 0) @@ -486,7 +487,7 @@ aloop: WAIT_EVENT_SSL_OPEN_SERVER); goto aloop; case SSL_ERROR_SYSCALL: - if (r < 0) + if (r < 0 && errno != 0) ereport(COMMERROR, (errcode_for_socket_access(), errmsg("could not accept SSL connection: %m"))); @@ -711,7 +712,7 @@ be_tls_read(Port *port, void *ptr, size_t len, int *waitfor) break; case SSL_ERROR_SYSCALL: /* leave it to caller to ereport the value of errno */ - if (n != -1) + if (n != -1 || errno == 0) { errno = ECONNRESET; n = -1; @@ -769,8 +770,14 @@ be_tls_write(Port *port, void *ptr, size_t len, int *waitfor) n = -1; break; case SSL_ERROR_SYSCALL: - /* leave it to caller to ereport the value of errno */ - if (n != -1) + + /* + * Leave it to caller to ereport the value of errno. However, if + * errno is still zero then assume it's a read EOF situation, and + * report ECONNRESET. (This seems possible because SSL_write can + * also do reads.) + */ + if (n != -1 || errno == 0) { errno = ECONNRESET; n = -1; diff --git a/src/backend/libpq/pqcomm.c b/src/backend/libpq/pqcomm.c index 9decd399ae7..7da63160690 100644 --- a/src/backend/libpq/pqcomm.c +++ b/src/backend/libpq/pqcomm.c @@ -1012,6 +1012,8 @@ pq_recvbuf(void) { int r; + errno = 0; + r = secure_read(MyProcPort, PqRecvBuffer + PqRecvLength, PQ_RECV_BUFFER_SIZE - PqRecvLength); @@ -1024,10 +1026,13 @@ pq_recvbuf(void) * Careful: an ereport() that tries to write to the client would * cause recursion to here, leading to stack overflow and core * dump! This message must go *only* to the postmaster log. + * + * If errno is zero, assume it's EOF and let the caller complain. */ - ereport(COMMERROR, - (errcode_for_socket_access(), - errmsg("could not receive data from client: %m"))); + if (errno != 0) + ereport(COMMERROR, + (errcode_for_socket_access(), + errmsg("could not receive data from client: %m"))); return EOF; } if (r == 0) @@ -1165,6 +1170,8 @@ pq_getbyte_if_available(unsigned char *c) /* Put the socket into non-blocking mode */ socket_set_nonblocking(true); + errno = 0; + r = secure_read(MyProcPort, c, 1); if (r < 0) { @@ -1181,10 +1188,13 @@ pq_getbyte_if_available(unsigned char *c) * Careful: an ereport() that tries to write to the client would * cause recursion to here, leading to stack overflow and core * dump! This message must go *only* to the postmaster log. + * + * If errno is zero, assume it's EOF and let the caller complain. */ - ereport(COMMERROR, - (errcode_for_socket_access(), - errmsg("could not receive data from client: %m"))); + if (errno != 0) + ereport(COMMERROR, + (errcode_for_socket_access(), + errmsg("could not receive data from client: %m"))); r = EOF; } } diff --git a/src/interfaces/libpq/fe-secure-openssl.c b/src/interfaces/libpq/fe-secure-openssl.c index 186799acf24..9a47ebef65c 100644 --- a/src/interfaces/libpq/fe-secure-openssl.c +++ b/src/interfaces/libpq/fe-secure-openssl.c @@ -207,7 +207,7 @@ rloop: */ goto rloop; case SSL_ERROR_SYSCALL: - if (n < 0) + if (n < 0 && SOCK_ERRNO != 0) { result_errno = SOCK_ERRNO; if (result_errno == EPIPE || @@ -315,7 +315,13 @@ pgtls_write(PGconn *conn, const void *ptr, size_t len) n = 0; break; case SSL_ERROR_SYSCALL: - if (n < 0) + + /* + * If errno is still zero then assume it's a read EOF situation, + * and report EOF. (This seems possible because SSL_write can + * also do reads.) + */ + if (n < 0 && SOCK_ERRNO != 0) { result_errno = SOCK_ERRNO; if (result_errno == EPIPE || result_errno == ECONNRESET) @@ -1354,10 +1360,12 @@ open_client_SSL(PGconn *conn) { int r; + SOCK_ERRNO_SET(0); ERR_clear_error(); r = SSL_connect(conn->ssl); if (r <= 0) { + int save_errno = SOCK_ERRNO; int err = SSL_get_error(conn->ssl, r); unsigned long ecode; @@ -1374,10 +1382,10 @@ open_client_SSL(PGconn *conn) { char sebuf[PG_STRERROR_R_BUFLEN]; - if (r == -1) + if (r == -1 && save_errno != 0) appendPQExpBuffer(&conn->errorMessage, libpq_gettext("SSL SYSCALL error: %s\n"), - SOCK_STRERROR(SOCK_ERRNO, sebuf, sizeof(sebuf))); + SOCK_STRERROR(save_errno, sebuf, sizeof(sebuf))); else appendPQExpBufferStr(&conn->errorMessage, libpq_gettext("SSL SYSCALL error: EOF detected\n")); diff --git a/src/interfaces/libpq/fe-secure.c b/src/interfaces/libpq/fe-secure.c index 3a736831564..3baad20c367 100644 --- a/src/interfaces/libpq/fe-secure.c +++ b/src/interfaces/libpq/fe-secure.c @@ -242,6 +242,8 @@ pqsecure_raw_read(PGconn *conn, void *ptr, size_t len) int result_errno = 0; char sebuf[PG_STRERROR_R_BUFLEN]; + SOCK_ERRNO_SET(0); + n = recv(conn->sock, ptr, len, 0); if (n < 0) @@ -269,6 +271,11 @@ pqsecure_raw_read(PGconn *conn, void *ptr, size_t len) "\tbefore or while processing the request.\n")); break; + case 0: + /* If errno didn't get set, treat it as regular EOF */ + n = 0; + break; + default: appendPQExpBuffer(&conn->errorMessage, libpq_gettext("could not receive data from server: %s\n"), --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
